The Masuda River connected the port town areas of Masuda with the castle town area, or the present-day Mito area, whereas the Takatsu River connected the port town areas with the Hikimi area.

Many port towns were scattered about the lagoon in the Masuda Plain, to which copper and silver from Tsumo Mine in Mito area was brought by the river.

Some river improvement works were done along with the development of castle town around Nanao castle and Miyake Odoi headquarters.

Masuda River was important for Masuda clan to run their territory rich, safe and stable.